'''
haha
'''
from threading import Thread


def output(content):
    while True:
        # flush 刷新，正常流不换行是不会输出的，需要缓存满后才能输出，flush能强制输出
        print(content, end='', flush=True)


def main():
    Thread(target=output, daemon=True, args=('Ping',)).start()
    Thread(target=output, daemon=True, args=('pong',)).start()
    print('hello,world!')


if __name__ == '__main__':
    main()
